I know this may be very simplistic of me, but looking at your room, I come to the following conclusion:
Your room mode profile:
You can see that your 2nd length mode is at 44Hz, and cannot be canceled by sub placement at the opposite ends of the room. You have a problem at 42Hz, I call that close enough. If you have a 42 Hz problem at seats 1,2 and 3, that is the problem; the 2nd order length mode. Your room also has a tangential mode at 44Hz per the calculations, harder to mess with. Unless sub placement is negotiable (1/4 the room dimensions along the sidewalls), you just have to try using delays or just EQ to get that peak out.
I know some people will throw out the fact that there are passageways connected to the room that will make the theoretical mode study above inaccurate, and they are correct. But I have also found that up to 3rd order modes in smaller rooms bear out in rooms that are mostly closed off, like yours.
SW3 in your setup is the only one that may be close to not exciting the 42Hz mode (near the 1/4 length dimension), and lo and behold, it is ~6dB down compared to the others. That is proof enough for me that you have a 2nd order length mode problem at 42Hz, that can be fixed with EQ for seats 1,2,3. Other seats may see a dip at 42Hz, but you can only do so much if sub and seating positions are limited.
Hope this helps,